Integrated Source of Path-Entangled Photon Pairs with Efficient Pump Self-Rejection.

Pablo De La Hoz,Dmitri Mogilevtsev,Matthew Thornton,Natalia Korolkova,Anton Sakovich,Alexander Mikhalychev

doi:10.3390/nano10101952

Abstract

We present a theoretical proposal for an integrated four-wave mixing source of narrow-band path-entangled photon pairs with efficient spatial pump self-rejection. The scheme is based on correlated loss in a system of waveguides in Kerr nonlinear media. We calculate that this setup gives the possibility for upwards of 100 dB pump rejection, without additional filtering. The effect is reached by driving the symmetric collective mode that is strongly attenuated by an engineered dissipation, while photon pairs are born in the antisymmetric mode. A similar set-up can additionally be realized for the generation of two-photon NOON states, also with pump self-rejection. We discuss the implementation of the scheme by means of the coherent diffusive photonics, and demostrate its feasibility in both glass (such as fused silica-glass and IG2) and planar semiconductor waveguide structures in indium phosphide (InP) and in silicon.

Highlights

The generation of photon pairs is a staple tool of modern quantum technologies
We present a theoretical proposal for an integrated four-wave mixing source of narrow-band path-entangled photon pairs with efficient spatial pump self-rejection
The effect is reached by driving the symmetric collective mode that is strongly attenuated by an engineered dissipation, while photon pairs are born in the antisymmetric mode

Summary

Introduction

The generation of photon pairs is a staple tool of modern quantum technologies. Twin photons have found far-reaching applications in a wide range of fields, from quantum communications to imaging, metrology, and LIDARs [1,2,3]. In the SFWM process, two photons are converted into signal and idler photons, and all four are of close frequencies, achieving large pump rejection can be challenging and it requires quite exquisite filtering [6] This is often accomplished via filtering setups far larger in size that the nonlinear device producing photon pairs. We suggest a novel and simple way for realizing efficient on-chip pump rejection by the SFWM process in a waveguide structure with engineered loss Nanomaterials 2020, 10, 1952 directional couplers is the use of the engineered non-linear loss as the main mechanism determining the device functionality [29,30,31]

Scheme

Operational Regime

Quantum Perturbation Theory

Realizations

Extention to NOON States

Conclusions